More MSan/ASan annotations.

This change lets us bootstrap LLVM/Clang under ASan and MSan. It contains
fixes for 2 issues:

- X86JIT reads return address from stack, which MSan does not know is
  initialized.
- bugpoint tests run binaries with RLIMIT_AS. This does not work with certain
  Sanitizers.

We are no longer including config.h in Compiler.h with this change.

llvm-svn: 174306
diff --git a/llvm/lib/Support/Unix/Program.inc b/llvm/lib/Support/Unix/Program.inc
index c384316..117151c 100644
--- a/llvm/lib/Support/Unix/Program.inc
+++ b/llvm/lib/Support/Unix/Program.inc
@@ -17,6 +17,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "Unix.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/FileSystem.h"
 #include <llvm/Config/config.h>
 #if HAVE_SYS_STAT_H
@@ -164,12 +165,16 @@
   setrlimit (RLIMIT_RSS, &r);
 #endif
 #ifdef RLIMIT_AS  // e.g. NetBSD doesn't have it.
+  // Don't set virtual memory limit if built with any Sanitizer. They need 80Tb
+  // of virtual memory for shadow memory mapping.
+#if !LLVM_MEMORY_SANITIZER_BUILD && !LLVM_ADDRESS_SANITIZER_BUILD
   // Virtual memory.
   getrlimit (RLIMIT_AS, &r);
   r.rlim_cur = limit;
   setrlimit (RLIMIT_AS, &r);
 #endif
 #endif
+#endif
 }
 
 bool